1. Field of the Invention
The present invention relates generally to flush mounted latches and locks of the type used with closures for industrial cabinets, tool carts, electrical equipment enclosures and the like. More particularly, the present invention relates to novel and improved latches and locks that utilize coaxially-pivoted sets of overlying latch bolt and operating arm components that are of novel form and that cooperate and co-act in a plurality of ways to provide desired types of latching and locking actions.
2. Prior Art
Flush mounted latches and locks that each include a body, a latch bolt movably carried on the body, and an operating handle that is nested by the body are well known. Normally the handle is in a flush or nested position when the bolt is in a latched position; and unlatching movement of the bolt is effected by moving the handle to an operating position. Latches and locks of this type are well suited for use on industrial cabinets, tool carts, electrical equipment enclosures and the like.
Flush-mounted latches and locks having pan-shaped housings that nest paddle-shaped operating handles, and that have spring-projected slide bolts are disclosed in such U.S. Pat. Nos. as 4,335,595, 4,321,812, 4,320,642, 4,312,205, 4,312,204, 4,312,203, 4,312,202, 4,309,884, 4,231,597, 4,138,869, 3,707,862, 3,668,907, 3,449,005, 3,389,932, 3,357,734, 3,209,564, 3,209,563, 3,055,204, 2,987,908, 2,900,204 and 2,642,300, all of which are assigned to the Eastern Company, a corporation of Connecticut.
Flush mounted latches and locks having latch bolts of other than the spring-projected, slide-mounted type are disclosed in such U.S. Pat. Nos. as 4,413,849, 4,320,642, 4,312,203, 4,134,281, 3,857,594, 3,338,610, 3,044,814, 3,044,287 and 2,735,706, all of which are assigned to the Eastern Company.
Latches having spring-biased pivotally-mounted latch bolts with hook-shaped arm portions projecting sidewardly from housings that enclose associated operating components, with the arm portions being "slammable" into latching engagement with suitably configured striker formations are disclosed in U.S. Pat. No. 4,511,166 assigned to the Eastern Company.
A cabinet latch having a housing that is usable with a variety of pivotally mounted latch bolts, and with a variety of latching mechanisms is disclosed in U.S. Pat. No. 4,177,656, also assigned to the Eastern Company.
3. Cross-Referenced & Referenced Patents & Applications
The present invention, taken together with the inventions that form the subjects matter of a select group of the cross-referenced and referenced utility and design patents and applications, require special comment inasmuch as these several inventions represent the work products of a long term and continuing development program. The group includes such cross-referenced and referenced cases as involve applications that either were put on file on July 10, 1987, or were filed as divisions or continuations of applications that were put on file on July 10, 1987. Thus the select group is comprised of cases that all relate back to cases that were filed July 10, 1987; and, the present case is appropriate to include within the select group inasmuch as it is a continuation-in-part of one of the cases of the select group, namely a case that was filed as a continuation-in-part of one of a total of sixteen applications that were put on file on July 10, 1987.
With respect to the cases of the select group, it should be understood that there are clear lines of demarcation among the subjects matter of each of these cases. The several functional features that form the subjects matter of the utility cases, and the several appearance features that form the subjects matter of the design cases, were developed by various co-workers, as is reflected in the listing of inventors in these cases. Many of the functional and appearance features that are claimed in separate ones of the utility and design cases developed substantially concurrently, especially as regards the subjects matter of the several companion cases that were put on file on July 10, 1987.
If an invention feature that is disclosed in one of the select group of utility and design cases constitutes a species of a development concept that is utilized in another of these related cases, it will be understood that care has been taken to present a generic claim in the case that describes the earliest development of a species that will support the generic claim. In this manner, a careful effort has been made to establish clear lines of demarcation among the claimed subjects matter of this and the several other utility and design cases of the select group. No two of these cases include claims of identical scope.
Referenced Utility Cases III(a) and III(b) disclose combinations of housing and handle assemblies that use spring-biased latch bolts that are pivotally mounted, with the latch bolts being configured and arranged so as to provide "slam-capable" latch and lock units--however, these units are not well suited for use on sliding doors, which is the principal application for latches and locks of the type that embody features of the present invention. Referenced Utility Case II, namely U.S. Pat. No. 4,841,755, discloses housing and handle combinations of the general type that preferably are utilized in latch and lock units that include features of the present invention. Design Cases I(a) and I(b), namely U.S. Pat. No. Des. 303,922 and co-pending divisional application Ser. No. 383,983, relate to appearance features of housings of said general type. Design Cases II, IV and VII, namely U.S. Pat. Nos. Des. 303,619, 303,618 and 303,620, respectively, relate to appearance features of housing and handle combinations that are of said general type. Design Cases VIII(a) and VIII(b), namely U.S. Pat. Nos. Des. 303,350 and 308,010, relate to appearance features of mounting brackets of the general type that can be used to mount latch and lock assemblies that embody the preferred practice of the present invention on closures of the type that are provided with openings that closely receive central body portions of said housings. Others of the cases of the select group disclose subjects matter that are believed to be of less relevance to features of the present invention.